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Ryanair flight landed at Manchester airport with six minutes of fuel left

theguardian.com

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Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#321

Post by mmaunder »

yieldcrv wrote: post #309
AceyMan wrote: post #68

Under FAA rules this was a screwup. [edit: see my own reply] (However, the rules are subtle, so they can be partially forgiven.) However, I'm not only a dispatcher but also a philosophy BA, so I've found a good way to explain it. Your reserve fuel (the "extra" fuel over what the actual flight burn) can of course be used (hello, that's what it's there for) but—and here's the rub—you can never plan on using it. That is…

in what way do FAA rules apply to operators doing a European to UK flight in an airline that doesn't operate in the US?

Similar philosophies but with differences. e.g. FAA reserve requirements is destination + alternate + 45 mins reserve. EASA is destination + alternate + final reserve which is 30 mins holding for jets and 45 mins for pistons IIRC. But in both cases it's that idea of a destination, an alternatite, and additional. And then there's the requirements around whether you need an alternate, etc.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#322

Post by al_borland »

loverofhumanz wrote: post #79
abtinf wrote: post #40

Earlier quoted context omitted.

Naively as an outsider, this situation seems like everything worked as intended? On a nominally 2h45m flight, they spent an extra 2 hours in the air, presumably doing doing fuel intensive altitude changing maneuvers, and were eventually able to land safely with their reserves almost exhausted. I’m a little confused by what there is to investigate at all. How much fuel should they have landed with?

"I’m a little confused by what there is to investigate at all." You're confused why they should investigate how everyone on that flight came within minutes of dying? Something about the fuel reserves, procedures, or execution was clearly flawed.

Or did it work as intended? The plane had multiple failed landing attempts, was re-routed, and had enough fuel to land safely. While no one wants to cut it this close, this was not a normal flight.

I’m not an expert in this field, but it would seem that the weight of extra fuel would increase operating costs, so it’s is effectively insurance. How much extra fuel should be carried to account for unplanned events like this, while not carrying so much that it becomes cost prohibitive.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#323

Post by awjlogan »

dzhiurgis wrote: post #299
cosmicgadget wrote: post #213

Earlier quoted context omitted.

Although credit is due to fuel reserve policies considering they landed after two diversions and three go arounds.

[flagged]

Why not? It's a factual report stating that the AAIB has opened an investigation into a potentially dangerous incident. There's not any editorial bias evident. See other extensive comments as to why this is not just a case of "it landed, so what's the problem?".

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#324

Post by mmaunder »

behringer wrote: post #112
AceyMan wrote: post #94

Earlier quoted context omitted.

Update: OK, if *Edinburgh* was their alternate and they missed there and were then forced to bugout for Manchester, that's then an example of when reserve is OK to be burned. (The 'slight simplification' I omitted was unpacking how the alternate fuel plays into the process, but here, that was a key part of the series of events.) That's what I get for not reading TFA first :-/

Not really, you should have enough fuel to make it to multiple alternatives or make emergency landing somewhere else. You should never burn that last 45 mins unless you want to make the news and file a lot of paperwork.

The regs are quite specific on if and when we need an alternate, which is weather dependent, and what your fuel requirements are. And we don't really have the idea of "multiple alternatives", but I guess it's implied by the additional reserve - what us Americans call a reserve or the Europeans call "final reserve". In case you're curious, we use the TAF (termimal area forecast) to determine if we need an alternate, and use a 1,2,3 rule which is 1 hour before and 1 hour after arrival time we need ceilings of at least 2000 ft and 3 statute miles of horizontal visibility.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#325

Post by johndubchak »

alwa wrote: post #209
jacquesm wrote: post #181

Earlier quoted context omitted.

(1) this was a jet, not a turboprop Edit: changed turbofan into turbprop, which is what I meant. (2) fuel burned stays burned, you don't 'get it back' (3) the altitude gained may have been adjusted to account for the low fuel situation (4) the winds are a major factor here, far larger than the fact that 'what goes up must come down', something that is already taken into account when computing the fuel reserve in the…

(1) The turbofan category of jet engine seems to inspire a lot of very pretty animated technical diagrams—here’s one set from a German manufacturer [0]. Now if only we could convince Bartozs Ciechanowski to take on such a subject… [1] (2) I know glider pilots who fly without any fuel at all, once aloft… sounds not unlike the 150-200km glide range that @MaxikCZ mentions at idle from cruising altitude. [0] https://aero…

Regarding the turbofan and [0], above...if you're communicating to a non-engineer (me), how does the design get to the point of such complexity? I would love to learn the design story behind such an incredibly complex piece of machinery.

I am being serious, if you cannot tell.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#326

Post by jacquesm »

bluGill wrote: post #276
jacquesm wrote: post #167

Earlier quoted context omitted.

That could be. We just don't know right now, but your intuition may well be correct, even if there is a single root cause there could very well be multiple contributory causes.

They failed to land at two airports before the third. I can't say if they made the right decisions but that already is two failures.

Go arounds are not failures.

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#327

Post by ChrisMarshallNY »

jacquesm wrote: post #23

That is very exceptional. I've written fuel estimation software for airliners (cargo, fortunately), and the number of rules regarding go-arounds, alternates and holding time resulted in there usually being quite a bit of fuel in the tanks on landing, by design. I've never heard of '6 minutes left' in practice where it wasn't a massive issue and the investigation into how this could have happened will make for interes…

> it shouldn't have happened, no matter what

You hear that a lot, with Ryanair stories.

Sounds like a great airline!

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#328

Post by tonyhart7 »

jacquesm wrote: post #121
kube-system wrote: post #100

Earlier quoted context omitted.

I'm not an aviation expert, but generally in safety engineering, safety buffers are not simply calculated as [normal situation] * [safety factor], but [worst case scenario] * [safety factor] If you ever cut into your safety allowance, you've already fucked up. Your expected design criteria should account for all use cases, nominal or worst-case. The safety factor is there for safety, it is never intended to be used.

This is exactly how it is in this case. Any consumption of the fuel reserve would result in an investigation, this is a very extreme case and it may even result in a change in the rules depending on the root cause.

Yeah idk people debating about this, if this justifiable then its all gucci and world can learn from such experience

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#329

Post by tonyhart7 »

nostrademons wrote: post #158
fidotron wrote: post #87

Earlier quoted context omitted.

I have known former air traffic controllers that won't fly certain airlines because of a notorious habit some have for queue jumping by claiming they're low on fuel. If they are low on fuel is something else, but in any case when the ATCs have noticed a pattern then something is up. This situation sounds a lot less nefarious, but it does also sound like they should have rerouted earlier.

Since there's a lot of confusion in the comments below I'm going to hijack one of the top comments to make a couple points clear from the article and FlightRadar24 data: [1] They did reroute earlier. It was 2 failed attempts on Prestwick (Glasgow), 45 minutes in the landing pattern, then they diverted to Edinburgh (15 minute flight), a failed attempt at Edinburgh (~5-10 minutes), and then they diverted to Manchester…

so the pilot fucked up either way right????

when you piece it together like that its a close call and maybe a hindsight but its understandable if pilot do this

Re: Ryanair flight landed at Manchester airport with six minutes of fuel left

#330

Post by jacquesm »

TheJoeMan wrote: post #251
abtinf wrote: post #40

Earlier quoted context omitted.

Naively as an outsider, this situation seems like everything worked as intended? On a nominally 2h45m flight, they spent an extra 2 hours in the air, presumably doing doing fuel intensive altitude changing maneuvers, and were eventually able to land safely with their reserves almost exhausted. I’m a little confused by what there is to investigate at all. How much fuel should they have landed with?

I think a more insightful answer is how often is it acceptable for the reserves to actually be cut into. If this was happening often, then there’s a likelihood of a future disaster. As it is there is 1 isolated case that still ended with a positive outcome. I think it almost adds support for the current reserve levels to be pretty dialed-in.

Officially: never. Unofficially, a minute or two would be cause for concern and the regulators would most likely be showing an interest. The airline may have a higher margin than the official one. This is exceptional, they were within the margin of error on readout and the pilots must have known that. It's one thing to know you have half an hour of fuel give-or-take in the tank it is another to know that give-or-take you are running on fumes.
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